package com.goldsign.pay.common.util.rsa;


import com.goldsign.pay.common.util.Base64Utils;
import sun.misc.BASE64Encoder;

import javax.crypto.Cipher;
import java.io.*;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
  
/** */

/**
 * <p> 
 * RSA公钥/私钥/签名工具包 
 * </p> 
 * <p> 
 * 罗纳德·李维斯特（Ron [R]ivest）、阿迪·萨莫尔（Adi [S]hamir）和伦纳德·阿德曼（Leonard [A]dleman） 
 * </p> 
 * <p> 
 * 字符串格式的密钥在未在特殊说明情况下都为BASE64编码格式<br/> 
 * 由于非对称加密速度极其缓慢，一般文件不使用它来加密而是使用对称加密，<br/> 
 * 非对称加密算法可以用来对对称加密的密钥加密，这样保证密钥的安全也就保证了数据的安全 
 * </p> 
 *  
 * @author IceWee 
 * @date 2012-4-26 
 * @version 1.0 
 */  
public class RsaUtils {  
  
    /**加密算法RSA **/  
    public static final String KEY_ALGORITHM = "RSA";  
      
    /** 签名算法 **/  
    public static final String SIGNATURE_ALGORITHM = "MD5withRSA";  
  
    /**获取公钥的key **/  
    private static final String PUBLIC_KEY = "PublicKey";  
      
    /**获取私钥的key**/  
    private static final String PRIVATE_KEY = "PrivateKey";  
      
    /*** RSA最大加密明文大小**/  
    private static final int MAX_ENCRYPT_BLOCK = 117;  
      
    /**RSA最大解密密文大小**/  
    private static final int MAX_DECRYPT_BLOCK = 128;  
  
    /** *//** 
     * <p> 
     * 生成密钥对(公钥和私钥) 
     * </p> 
     *  
     * @return 
     * @throws Exception 
     */  
    public static Map<String, Object> genKeyPair() throws Exception {  
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);  
        keyPairGen.initialize(1024);  
        KeyPair keyPair = keyPairGen.generateKeyPair();  
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();  
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        System.out.println("【keyPair.getPublic()】"+keyPair.getPublic());
        System.out.println("【keyPair.getPrivate()】"+keyPair.getPrivate());
        byte[] publicKeyBytes = new BASE64Encoder().encode(keyPair.getPublic().getEncoded()).getBytes();
        byte[] prvateKeyBytes = new BASE64Encoder().encode(keyPair.getPrivate().getEncoded()).getBytes();
        FileOutputStream fos = new FileOutputStream("PublicKey.keystore");
        fos.write(publicKeyBytes);
        fos = new FileOutputStream("PrivateKey.keystore");
        fos.write(prvateKeyBytes);
        Map<String, Object> keyMap = new HashMap<String, Object>(2);  
        keyMap.put(PUBLIC_KEY, publicKey);  
        keyMap.put(PRIVATE_KEY, privateKey);  
        return keyMap;  
    }  
      
    /** *//** 
     * <p> 
     * 用私钥对信息生成数字签名 
     * </p> 
     *  
     * @param data 已加密数据 
     * @param privateKey 私钥(BASE64编码) 
     *  
     * @return 
     * @throws Exception 
     */  
    public static String sign(byte[] data, String privateKey) throws Exception {  
        byte[] keyBytes = Base64Utils.decode(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);  
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);  
        PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);  
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);  
        signature.initSign(privateK);  
        signature.update(data);  
        return Base64Utils.encode(signature.sign());  
    }  
  
    /** *//** 
     * <p> 
     * 校验数字签名 
     * </p> 
     *  
     * @param data 已加密数据 
     * @param publicKey 公钥(BASE64编码) 
     * @param sign 数字签名 
     *  
     * @return 
     * @throws Exception 
     *  
     */  
    public static boolean verify(byte[] data, String publicKey, String sign)  
            throws Exception {  
        byte[] keyBytes = Base64Utils.decode(publicKey);  
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);  
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);  
        PublicKey publicK = keyFactory.generatePublic(keySpec);  
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);  
        signature.initVerify(publicK);  
        signature.update(data);  
        return signature.verify(Base64Utils.decode(sign));  
    }  
  
    /** *//** 
     * <P> 
     * 私钥解密 
     * </p> 
     *  
     * @param encryptedData 已加密数据 
     * @param privateKey 私钥(BASE64编码) 
     * @return 
     * @throws Exception 
     */  
    public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey)  
            throws Exception {  
        byte[] keyBytes = Base64Utils.decode(privateKey);  
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);  
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);  
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);  
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());  
        cipher.init(Cipher.DECRYPT_MODE, privateK);  
        int inputLen = encryptedData.length;  
        ByteArrayOutputStream out = new ByteArrayOutputStream();  
        int offSet = 0;  
        byte[] cache;  
        int i = 0;  
        // 对数据分段解密  
        while (inputLen - offSet > 0) {  
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {  
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);  
            } else {  
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);  
            }  
            out.write(cache, 0, cache.length);  
            i++;  
            offSet = i * MAX_DECRYPT_BLOCK;  
        }  
        byte[] decryptedData = out.toByteArray();  
        out.close();  
        return decryptedData;  
    }  
  
    /** *//** 
     * <p> 
     * 公钥解密 
     * </p> 
     *  
     * @param encryptedData 已加密数据 
     * @param publicKey 公钥(BASE64编码) 
     * @return 
     * @throws Exception 
     */  
    public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey)  
            throws Exception {  
        byte[] keyBytes = Base64Utils.decode(publicKey);  
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);  
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);  
        Key publicK = keyFactory.generatePublic(x509KeySpec);  
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());  
        cipher.init(Cipher.DECRYPT_MODE, publicK);  
        int inputLen = encryptedData.length;  
        ByteArrayOutputStream out = new ByteArrayOutputStream();  
        int offSet = 0;  
        byte[] cache;  
        int i = 0;  
        // 对数据分段解密  
        while (inputLen - offSet > 0) {  
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {  
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);  
            } else {  
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);  
            }  
            out.write(cache, 0, cache.length);  
            i++;  
            offSet = i * MAX_DECRYPT_BLOCK;  
        }  
        byte[] decryptedData = out.toByteArray();  
        out.close();  
        return decryptedData;  
    }  
  
    /** *//** 
     * <p> 
     * 公钥加密 
     * </p> 
     *  
     * @param data 源数据 
     * @param publicKey 公钥(BASE64编码) 
     * @return 
     * @throws Exception 
     */  
    public static byte[] encryptByPublicKey(byte[] data, String publicKey)  
            throws Exception {  
        byte[] keyBytes = Base64Utils.decode(publicKey);  
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);  
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);  
        Key publicK = keyFactory.generatePublic(x509KeySpec);  
        // 对数据加密  
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());  
        cipher.init(Cipher.ENCRYPT_MODE, publicK);  
        int inputLen = data.length;  
        ByteArrayOutputStream out = new ByteArrayOutputStream();  
        int offSet = 0;  
        byte[] cache;  
        int i = 0;  
        // 对数据分段加密  
        while (inputLen - offSet > 0) {  
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {  
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);  
            } else {  
                cache = cipher.doFinal(data, offSet, inputLen - offSet);  
            }  
            out.write(cache, 0, cache.length);  
            i++;  
            offSet = i * MAX_ENCRYPT_BLOCK;  
        }  
        byte[] encryptedData = out.toByteArray();  
        out.close();  
        return encryptedData;  
    }  
  
    /** *//** 
     * <p> 
     * 私钥加密 
     * </p> 
     *  
     * @param data 源数据 
     * @param privateKey 私钥(BASE64编码) 
     * @return 
     * @throws Exception 
     */  
    public static byte[] encryptByPrivateKey(byte[] data, String privateKey)  
            throws Exception {  
        byte[] keyBytes = Base64Utils.decode(privateKey);  
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);  
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);  
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);  
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());  
        cipher.init(Cipher.ENCRYPT_MODE, privateK);  
        int inputLen = data.length;  
        ByteArrayOutputStream out = new ByteArrayOutputStream();  
        int offSet = 0;  
        byte[] cache;  
        int i = 0;  
        // 对数据分段加密  
        while (inputLen - offSet > 0) {  
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {  
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);  
            } else {  
                cache = cipher.doFinal(data, offSet, inputLen - offSet);  
            }  
            out.write(cache, 0, cache.length);  
            i++;  
            offSet = i * MAX_ENCRYPT_BLOCK;  
        }  
        byte[] encryptedData = out.toByteArray();  
        out.close();  
        return encryptedData;  
    }  
  
    /** *//** 
     * <p> 
     * 获取私钥 
     * </p> 
     *  
     * @param keyMap 密钥对 
     * @return 
     * @throws Exception 
     */  
    public static String getPrivateKey(Map<String, Object> keyMap)  
            throws Exception {  
        Key key = (Key) keyMap.get(PRIVATE_KEY);  
        return Base64Utils.encode(key.getEncoded());  
    }  
  
    /** *//** 
     * <p> 
     * 获取公钥 
     * </p> 
     *  
     * @param keyMap 密钥对 
     * @return 
     * @throws Exception 
     */  
    public static String getPublicKey(Map<String, Object> keyMap)  
            throws Exception {  
        Key key = (Key) keyMap.get(PUBLIC_KEY);  
        return Base64Utils.encode(key.getEncoded());  
    }  
    
    public static void main(String[] args) throws Exception {
//    	 genKeyPair();
//    	 System.out.println(ClassLoader.getSystemResource("")); 
//    	 AppSignManager.setSignMap("epaylinks.global.payment", map);
//    	 System.out.println("【公钥】："+map.get(PUBLIC_KEY)+"    【私钥】："+map.get(PRIVATE_KEY));
//    	System.out.println("【取出来的私钥】："+AppSignManager.getPrivateKey("epaylinks.global.payment"));
    	String yw = "93c53cca25c84bea3e11e43a906d5162";
    	String mw = "kDWmafM+XygD8dfSx7x2tArrBnZ781LyPCDyNzw7dz/91v6fFOmwyWITXJmuNiUHS4xy1hmfhpH84heeRg5mb8NXAcoRlxp0jXGvRIZ/oB4gaS4xvTO89SURnhMqz1lWlTJDLRoTuIuje8CLlpBG47LTGCdziU1ExWvGDfXP0+o=";
    	InputStream is = new FileInputStream(new File("D:\\system\\Decktop\\temp\\PrivateKey_ser.keystore"));
    	StringBuilder sb = new StringBuilder();
    	BufferedReader br = null;
    	InputStreamReader inputStreamReader=new InputStreamReader(is);
    	br = new BufferedReader(inputStreamReader); 
        String readLine = null;  
        while ((readLine = br.readLine()) != null) {  
            sb.append(readLine);  
        }  
        br.close();  
        byte[] res = decryptByPrivateKey(mw.getBytes(), sb.toString());
        System.out.println("解密结果："+Base64Utils.encode(res));

    	
	}
}  